The 3750 should support MLS - configure your SVIs on that switch. 2950s only support a single SVI with an IP - it is NOT multi-layer switching capable. Each time you "no shut" an SVI with an IP on it, the current one will shut down.

With that said, ensure "ip routing" is turned on the 3750, ensure MLS is on(depending on the code you're running), then configure all of your SVIs on the 3750. Once that is done, create a dot1q trunk to the 2950 and ensure the VLANs(NOT SVIs, VLANS) are created ont he 2950.

Travis's post is the answer you are looking for. Layer 2 switches can only have 1 svi up at a time. What ever Vlan you want the management ip of your switch to reside in is the sci the switch needs to have. There is no need to have multiple svi's on a layer 2 switch.

In my case I will usually have 3 vlans on a switch. A data Vlan, a voice Vlan and a management Vlan. The switches svi would be on the management Vlan and then car layer 2 vlans for voice and data.